全文获取类型
收费全文 | 2469篇 |
免费 | 172篇 |
国内免费 | 1篇 |
出版年
2023年 | 4篇 |
2022年 | 6篇 |
2021年 | 28篇 |
2020年 | 14篇 |
2019年 | 34篇 |
2018年 | 46篇 |
2017年 | 35篇 |
2016年 | 49篇 |
2015年 | 81篇 |
2014年 | 109篇 |
2013年 | 184篇 |
2012年 | 158篇 |
2011年 | 195篇 |
2010年 | 112篇 |
2009年 | 109篇 |
2008年 | 189篇 |
2007年 | 175篇 |
2006年 | 176篇 |
2005年 | 147篇 |
2004年 | 157篇 |
2003年 | 151篇 |
2002年 | 147篇 |
2001年 | 14篇 |
2000年 | 22篇 |
1999年 | 33篇 |
1998年 | 30篇 |
1997年 | 23篇 |
1996年 | 14篇 |
1995年 | 12篇 |
1994年 | 21篇 |
1993年 | 16篇 |
1992年 | 23篇 |
1991年 | 15篇 |
1990年 | 16篇 |
1989年 | 15篇 |
1988年 | 18篇 |
1987年 | 10篇 |
1986年 | 3篇 |
1985年 | 4篇 |
1984年 | 4篇 |
1983年 | 4篇 |
1982年 | 5篇 |
1981年 | 8篇 |
1980年 | 7篇 |
1979年 | 3篇 |
1977年 | 3篇 |
1976年 | 2篇 |
1975年 | 4篇 |
1974年 | 2篇 |
1959年 | 1篇 |
排序方式: 共有2642条查询结果,搜索用时 31 毫秒
21.
Hidehiko Kumagai Nobukazu Kashima Hiroshi Torii Hideaki Yamada Hitoshi Enei Shinji Okumuea 《Bioscience, biotechnology, and biochemistry》2013,77(3):472-482
Crystalline tyrosine phenol lyase was prepared from the cell extract of Erwinia herbicola grown in a medium supplemented with l-tyrosine. The crystalline enzyme was homogeneous by the criteria of ultracentrifugation and acrylamide gel electrophoresis. The molecular weight was determined to be approximately 259,000. The crystalline enzyme catalyzed the conversion of l-tyrosine into phenol, pyruvate and ammonia, in the presence of added pyridoxal phosphate. The enzyme also catalyzed pyruvate formation from d-tyrosine, S-methyl-l-cysteine, 3, 4-dihydroxyphenyl-l-alanine, l- and d-serine, and l- and d-cysteine, but at lower rates than from l-tyrosine. l-Phenyl-alanine, l-alanine, phenol and pyrocatechol inhibited pyruvate formation from l-tyrosine.Crystalline tyrosine phenol lyase from Erwinia herbicola is inactive in the absence of added pyridoxal phosphate. Binding of pyridoxal phosphate to the apoenzyme is accompanied by pronounced increase in absorbance at 340 and 425 mμ. The amount of pyridoxal phosphate bound to the apoenzyme was determined by equilibrium dialysis to be 2 moles per mole of enzyme. Addition of the substrate, l-tyrosine, or the competitive inhibitors, l-alanine and l-phenyl-alanine, to the holoenzyme causes appearance of a new absorption peak near 500 mμ which disappears as the substrate is decomposed but remains unchanged in the presence of the inhibitor. 相似文献
22.
Shinji Yoshitake Gunki Funatsu Masaru Funatsu 《Bioscience, biotechnology, and biochemistry》2013,77(6):1267-1274
Sixteen peptic peptides, which contain arginine(s) or lysine, were isolated from cyanogen bromide fragments CB I and CB II of Ile-chain. Sequence determination has been performed on most of these peptides to provide overlaps for the tryptic peptides. Thus, complete amino acid sequence of Ile-chain consisting of 265 amino acid residues was determined. Some structural characteristics of the protein are also discussed. 相似文献
23.
24.
Haruo Misono Kouji Sugihara Yumiko Kuwamoto Shinji Nagata Susumu Nagasaki 《Bioscience, biotechnology, and biochemistry》2013,77(6):1491-1498
Leucine dehydrogenase [EC 1.4.1.9] was purified to homogeneity from Corynebacterium pseudodiphtheriticum ICR 2210. The enzyme consisted of a single polypeptide with a molecular weight of about 34,000. Stepwise Edman degradation provided the N-terminal sequence of the first 24 amino acids, and carboxypeptidase Y digestion provided the C-terminal sequence of the last 2 amino acids. Although the enzyme catalyzed the reversible deamination of various branched-chain l-amino acids, l-valine was the best substrate for oxidative deamination at pH 10.9 and the saturated concentration. The enzyme, however, had higher reactivity for l-leucine, and the kcat/Km value for l-leucine was higher than that for l-valine. The enzyme required NAD+ as a natural coenzyme. The NAD+ analogs 3-acetylpyridine-NAD+ and deamino-NAD+ were much better coenzymes than NAD +. The enzyme activity was significantly reduced by sulfhydryl reagents and pyridoxal 5′-phosphate. d-Enantiomers of the substrate amino acids competitively inhibited the oxidation of l-valine. 相似文献
25.
Tateki Hayashi Akihiko Terao Shinji Ueda Mitsuo Namiki 《Bioscience, biotechnology, and biochemistry》2013,77(11):3139-3144
Ascorbic acid-protein mixtures of low moisture content stored for 2~3 days in aerobic conditions at 60°C produced a red coloration, which was shown to have resulted from an amino-carbonyl reaction of oxidized ascorbic acid (dehydroascorbic acid, DHA) by the facts that DHA-casein or ovalbumin systems yielded a rapid red coloration in low moisture conditions as well as in an ethanol suspension. Zein showed only a weak red coloration with DHA. An apparent decrease in the free amino group, as determined by the TNBS method, was observed to be associated in parallel with the red pigment formation. The electrophoretic pattern of ovalbumin changed significantly upon incubation with DHA, together with the formation of the red pigment. The red pigment extracted from a DHA-casein system showed an absorption spectrum, TLC Rf value, and hydrolyzed products (DHA and scorbamic acid) identical to those of 2,2′-nitrilo di-2(2)-deoxy-l-ascorbic acid mono ammonium salt, produced from DHA and amino acid. Formation of the red pigment was also observed in the reaction of DHA with Nα-acetyl lysine. These results indicate that the ε-amino group of lysine in protein can be attributed to the formation of a red pigment identical with NDA. 相似文献
26.
Jiro Sekiya Shinji Numa Tadahiko Kajiwara Akikazu Hatanaka 《Bioscience, biotechnology, and biochemistry》2013,77(1):185-190
The synthetic activity for 3Z-hexenal, an important precursor of 3Z-hexenol (leaf alcohol), was localized in chloroplasts of Thea sinensis leaves. 3Z-Hexenal, which is easily isomerized to 2E-hexenal (leaf aldehyde), was formed from linolenic acid in the presence of oxygen. 13-l-Hydroperoxy-linolenic acid also served as a precursor, but the triglyceride and methyl ester of linolenic acid did not. This enzyme system appeared to be tightly bound to the lamellae membranes of chloroplasts. 相似文献
27.
Akira Kuninaka Masao Kumagai Kazuo Fujiyama Masaru Ogura Shinji Sakata Seishiro Yonei 《Bioscience, biotechnology, and biochemistry》2013,77(6):1437-1439
Substance B, the major component, isolated from rice plant treated with probenzaole and inoculated, having anti-conidial germination activity against blast fungus, was found to be a mixture of fatty acids, including palmitic acid, linoleic acid and linolenic acid. The main compound of substance B was linolenic acid, having strong anti-conidial germination activity. It was determined as α-linolenic acid by gas chromatographic analysis. The minor components showed little or no anti-conidial germination activity. 相似文献
28.
Shengchen Tao Daiju Yamazaki Shinji Komazaki Chengzhu Zhao Tsunaki Iida Sho Kakizawa Yuji Imaizumi Hiroshi Takeshima 《The Journal of biological chemistry》2013,288(22):15581-15589
The TRIC channel subtypes, namely TRIC-A and TRIC-B, are intracellular monovalent cation-specific channels and likely mediate counterion movements to support efficient Ca2+ release from the sarco/endoplasmic reticulum. Vascular smooth muscle cells (VSMCs) contain both TRIC subtypes and two Ca2+ release mechanisms; incidental opening of ryanodine receptors (RyRs) generates local Ca2+ sparks to induce hyperpolarization and relaxation, whereas agonist-induced activation of inositol trisphosphate receptors produces global Ca2+ transients causing contraction. Tric-a knock-out mice develop hypertension due to insufficient RyR-mediated Ca2+ sparks in VSMCs. Here we describe transgenic mice overexpressing TRIC-A channels under the control of a smooth muscle cell-specific promoter. The transgenic mice developed congenital hypotension. In Tric-a-overexpressing VSMCs from the transgenic mice, the resting membrane potential decreased because RyR-mediated Ca2+ sparks were facilitated and cell surface Ca2+-dependent K+ channels were hyperactivated. Under such hyperpolarized conditions, L-type Ca2+ channels were inactivated, and thus, the resting intracellular Ca2+ levels were reduced in Tric-a-overexpressing VSMCs. Moreover, Tric-a overexpression impaired inositol trisphosphate-sensitive stores to diminish agonist-induced Ca2+ signaling in VSMCs. These altered features likely reduced vascular tonus leading to the hypotensive phenotype. Our Tric-a-transgenic mice together with Tric-a knock-out mice indicate that TRIC-A channel density in VSMCs is responsible for controlling basal blood pressure at the whole-animal level. 相似文献
29.